As an important unit in the fix-appliance technique, a bracket is a correction instrument for correcting deformity of the teeth. The bracket can be bonded directly to the surface of dental crowns, and various types of orthodontic forces can be applied to the tooth by an arch wire via the bracket, so as to realize orthodontic treatment.
At present, all of the traditional brackets are square, with a protruding limb for fixing the arch wire provided on each corner of the bracket. The mucous membrane of a patient's mouth may be stung by the protruding limb and the patient may feel uncomfortable. In addition, food, such as vegetable leaves, may be retained by the bracket when the patient is eating, which can be detrimental for oral health, or may even cause more accumulation of tartar and dental plaque.